Acid gas burner

ABSTRACT

A burner for feeding acid (H2S) gas to a combustion chamber of a thermal reactor contains a gas-feeding tube having a forward flared open end, that extends horizontally through a wall of the reactor into the chamber, and a gas diverter concentrically disposed in that open end to provide an annular space between the diverter and the flared open end of the tube. The diverter has a rearward portion with a frustoconical surface facing the inner surface of that flared end of the tube. The diverter is connected at its rear end, inside the tube, to one end of a shaft that extends rearwardly through the tube to an external location for its other end. The shaft adjacent that other end is connected to means to move the shaft longitudinally for adjustment of the dimension of the annular space between the diverter and the flared end of the tube. The burner further includes an intermediate support for the movable shaft. The intermediate support is mounted on the tube adjacent its flared end. The shaft is also supported adjacent its other end.

United States Patent 11 1 Shumaker 1 1 Jan. 1,1974

[ ACID GAS BURNER [75] Inventor: Willis L. Shumaker, Independence,

211 Appl. No.: 251,660

[52] U.S. Cl. 431/186, 239/417.3, 239/424, 239/456, 431/187 [51] Int.Cl. F23c 5/06 [58] Field of Search 431/171, 186, 187, 431/188, 189;239/417.3, 424, 456, 460

[56] 1 References Cited UNITED STATES PATENTS 1,563,246 11/1925 Zulver431/171 2,914,257 11/1959 Wiant 239/460 1,996,545 4/1935 Knowlt0n....239/460 823,836 6/1906 Wiemann 431/186 3,123,127 3/1964 Willott 431/1861,779,647 10/1930 Van Brunt 431/186 Primary E.raminerCarroll B. Dority,Jr. AttorneyClaron N. White et al.

[57] ABSTRACT A burner for feeding acid (H 8) gas to a combustionchamber of a thermal reactor contains a gas-feeding tube having aforward flared open end, that extends horizontally through a wall of thereactor into the chamber, and a gas diverter concentrically disposed inthat open end to provide an annular space between the diverter and theflared open end of the tube. The diverter has a rearward portion with afrustoconical surface facing the inner surface of that flared end of 1the tube. The diverter is connected at its rear end, inside the tube, toone end of a shaft that extends rearwardly through the tube to anexternal location for its other end. The shaft adjacent that other endis connected to means to move the shaft longitudinally for adjustment ofthe dimension of the annular space between the diverter and the flaredend of the tube. The burner further includes an intermediate support forthe movable shaft. The intermediate support is mounted on the tubeadjacent its flared end. The shaft is also supported adjacent its otherend.

7 9 Claims, 4 Drawing Figures 1 ACID GAS BURNER BACKGROUND OF THEINVENTION l. Field of the Invention This invention relates to an acidgas burner for a thermal reactor of a sulfur plant i.e., a plant for therecovery of sulfur from hydrogen sulfide. The gas containing hydrogensulfide is fed by the burner to a combustion chamber of a thermalreactor where hydrogen sulfide is burned by oxygen in air to form sulfurdioxide. Con ventionally, one-third of the volume of hydrogen sulfide isthus converted. The combustion product gas is cooled and then passedthrough a catalytic reactor, in which the formed sulfur dioxide reactswith hydrogen sulfide remaining to form elemental sulfur, that is thencondensed and separated from the gas.

2. Description of the Prior Art The recovery of elemental sulfur as aby-product from various processes is described at pages 352-354 ofvolume 19 of Kirk-Othmer Encyclopedia of Chemical Technology, secondcompletely revised edition, published by lnterscience Publishers, adivision of John Wiley & Sons, Inc., New York, N.Y. In that descriptionit is stated that in sour natural gas sulfur is present as hydrogensulfide. It is also stated that in petroleum refining gases are obtainedthat contain hydrogen sulfide. In either case, the hydrogen sulfide isremoved by absorption in a solution of alkanolamine, which upon heatinggives up its hydrogen sulfide in concentrated form. The descriptionincludes a generalized flowsheet for this separation of hydrogen sulfideand the subsequent treatment to form elemental sulfur. Descriptions ofprocesses for this supplemental treatment are presented in the articlesentitled Package plants for sulfur recovery," Chemical EngineeringProgress, (Vol. 61, No. 9) September 1965, at pages 70-73 and Watchthese trends in Sulfur plant design, Hydrocarbon Processing, March 1972,at pages 105-108. Apparatuses for the treatment processes for sulfurrecovery from H s-containing gas are disclosedand claimed in U. 5. Pat.Nos. 2,889,207 and 2,939,769.

As seen in U. S. Pat. No. 2,889,207, the gas rich in hydrogen sulfide isburned with air in a furnace, i.e., a thermal reactor in which thetemperature may range as high as 2,000 to 2,500 F. This gas leaves thefurnace and enters a waste heat boiler to cool the gas to 400600 F.before passage into a catalytic converter. In the other patent mentionedabove the apparatus is constructed so that the furnace is integral withthe boiler as part of a highly efficient and compact sulfur recoveryplant.

A burner, commonly known as an acid gas burner, is used to feed the HS-rich gas to the combustion chamber where it mixes with and reacts withair. An acid gas burner used prior to the present invention comprises atube or pipe having one end extending into the combustion chamber with abulbous cap mounted on the end and having its convex surface facing thechamber. The cap has concentric sets of holes through it to providediverging streams of flow of the gas from the tube into the combustionchamber. The cap has a central recess in which is locatedheat-insulating material. Part of the H 8 content of the gas that ispassed through these concentric sets of holes is burned primarily to50:. This burner is mounted in a side wall of the reactor and extendsthrough and is concentric with a larger tube or pipe into which is fedair from a blower. The air passes into the chamber through an annularspace between the burner tube and the larger pipe. The mixing of air andacid gas adjacent the cap or burner tip and the high reactiontemperature obtained causes build-up of iron sulfide scale, due to thecorrosive nature of H 8, and causes deformation of the burner tip,resulting in high pressure drop and back pressure. This restricted thethroughout of the acid gas so that burning part of it in the atmosphere,commonly called flaring, was necessary. The high back pressureundesirably caused a higher amine stripper pressure and thisnecessitated the use of a higher reboiler temperature.

A recently developed acid gas burner avoided the construction of an endcap with its set of holes that m desirably can decrease in size withuse, as mentioned above. That burner has its tube flared at the endextending into the combustion chamber. Rigidly mounted on the tube inthat open end is a diverter concentrically disposed. The divertercomprises a cone-shaped metal sheet connected at its outer surfaceadjacent its edge to the flared portion of the burner tube by a numberofequally spaced radial metal webs, as a fixed spider support arrangement.This construction provides basically an annular passage for the gas fromthe pipe to the combustion chamber. The concave side of the conicalsheet faces outwardly, i.e., toward the combustion chamber and that sideof the sheet contains a lining of heat-insulating refractory cast inplace and containing embedded in it a number of wires connected to themetal sheet to secure the refractory to the conical sheet. Therefractory protects the metal sheet to some extent from the hightemperature inthe combustion furnace, but the corrosion of the metalremains so that there still is the problem of decrease of size of theannular passage during use of the burner.

The sulfur plant in a petroleum refinery can receive feed from severalunits. Also there is a variation in the sulfur content of crude oilsused in a refinery. These factors result in a wide range of flow of acidgas and in a wide range of burner pressure. There can be as much as afivefold variation in flow of acid gas to be treated. The burners of theprior art that have been mentioned above are not capable of compensatingfor such variations or change in passage area with use, although as 1regarding the change in area the later developed burner of the prior artis a substantial improvement over the previous construction, thoseburners do not permit compensation for such variations to provide auniform flame pattern in the combustion chamber. They lack the abilityto avoid excessive back pressure from either fouling or high flow.

SUMMARY OF THE INVENTION This invention relates to an acid gas burneruseful for feeding to a combustion chamber of a thermal reactor a gascontaining H 5 for the oxidation of a part of the H 5 to S0 by air alsofed to the chamber. The burner comprises a tube with a flared open endfor feeding the acid gas to the chamber. In use the tube extends intothe chamber through a larger tube with which it is concentricallydisposed to provide an annular passage of air between the two tubes intothe chamber. The larger tube is mounted at an opening in the side wallof the combustion chamber. The burner also includes a diverterconcentrically disposed at that open end of the tube. The rearwardportion of the diverter has a frustoconical surface facing the innersurface of that flared end of the tube so as to provide an annular spacebetween them. To this extent the burner of the present invention has aconstruction similar to the recently developed gas bumer mentionedabove. However, instead of the diverter being rigidly mounted on thetube at its flared open end, the burner of the present invention has thediverter connected to a shaft for its support, and the shaft extendsrearwardly through the tube to an external location for its other end.The burner further includes means to move the shaft longitudinally formovement of the diverter relative to the tube for adjusting the changein the dimensions of the annular passage between the diverter and theflared open end of the tube. The burner of this invention also includesmeans to support the shaft adjacent its other end and means to supportthe shaft adjacent its end on which is mounted the diverter.

Due to this construction, the burner of the present invention cancompensate for any change in passage area due to scale build-up and canbe adjusted to provide a uniform flame pattern and to avoid excessiveback pressure resulting from substantial change in flow of acid gas tothe tube of the burner. As seen below, the diverter can be constructedentirely of refractory material and thus, except for the flared end ofthe tube, can avoid the scale formation that occurs with the burner,mentioned above, that required the conical metal sheet for rigidlyconnecting the diverter by metal webs, i.e., radial metal plates, to thetube for annular flow of acid gas to the combustion chamber.

The burner of the present invention has another advantage due to itsadjustability of the area of the annular passage by movement of thediverter through longitudinal, i.e., axial movement of the shaft. Themovement can be controlled automatically by means responsive to changein rate of flow of acid gas to the burner.

DESCRIPTION OF THE DRAWINGS Preferred embodiments of the burner of thepresent invention are illustrated in the drawings in which generallysimilar parts are identified by the same numerals and in which:

FIG. 1 is a fragmentary longitudinal section ofa thermal reactor of asulfur plant showing mounted in position an especially preferredembodiment of the acid gas burner of the present invention.

FIG. 2 is a cross-section taken along the line 22 of FIG. 1.

FIG. 3 is a fragmentary view of the thermal reactor showing analternative construction for the burner when its tube for feeding gasdoes not have a curved construction external of the reactor but ratheris straight throughout and has a side opening, adjacent its closed andexternal of the reactor, for connection to a feed pipe that provides itwith acid gas.

FIG. 4 is a fragmentary view of the burner showing another embodiment ofconstruction for the diverter of the burner.

DETAILED DESCRIPTION FIG. 1 shows a thermal reactor generally indicatedat 11 containing a combustion chamber 12 enclosed by a housing 13internally lined with a refractory l4 and having a heat insulatingjacket 15. The housing 13 is enclosed at one'end by a circular end plate16 having an opening 17. The refractory lining 14 has an opening alignedwith opening 17 of plate 16. This construction provides an inlet openingfor chamber 12.

A large pipe 18 is mounted on plate 16 so that one end of pipe 18 is atopening 17 of plate 16. The other end of pipe 18 is closed by a plate19. A larger pipe 20 is concentric with pipe 18. One end of pipe 20 isfit over plate 16. The other end of pipe 20 has a flange 21 that isbolted to plate 19 by bolts 22 and nuts 23. The pipe 20 has an opening24 at which a pipe 25 is connected to pipe 20. The pipe 25 is connectedto an air blower (not shown) that feeds air by pipe 25 to the annularspace between pipes 18 and 20. The pipe 18 has two large oval openings26 facing each other and disposed relative to opening 24 in pipe 20. Byopenings 26 air received in the annular space between pipes 18 and 20passes into pipe 18 and then passes from it through the opening 17 ofplate 16 into chamber 12.

Concentrically disposed within pipe 18 is the forward end of a tube 27of one embodiment of the acid gas burner of the present invention andgenerally indicated at 28. That forward portion of tube 27 extendsthrough opening 17 to chamber 12 and has a flared open end 29. With thisconstruction of the forward end of the tube 27 and its disposition intube 18, air in pipe 18 travels to chamber 12 in an annular path fromthe time it passes through the opening 17 of plate 16.

Disposed in pipe 18 around this forward end portion of tube 27,equidistant from it and extending into chamber 12 is a parallel set ofpilot burners (not shown) that have their tips directed toward thelongitudinal axis of pipe 18 and that are conventionally supported byand communicating with a plenum ring (not shown) communicating with apipe (not shown) extending through plate 19 and connected to a fuel gassupply (not shown). Also in pipe 18 is an igniter assembly (not shown)that extends through plate 19, through opening 17 of plate 16 and intochamber 12. The igniter assembly has its own feed pipes for gas and air.That assembly is used to provide initial combustion to light the pilotburners that are used only during start-up of thermal reactor 11. Ofcourse, the igniter assembly and the set of pilot burners are externalof tube 27 and extend through the annular space between it and opening17 of plate 16. The use of the igniter assembly and the pilot burners isconventional with the earlier acid gas burners of the prior artmentioned above.

The acid gas burner 28 has its tube 27, in the embodiment shown in FIG.1, constructed with a curved rearward portion that is external of thehousing provided by pipe 18 and plate 19. This curved portion of pipe 27has an opening 30 in alignment with the longitudinal axis of thestraight forward portion of tube 27 that is within pipe 18 and extendsinto chamber 12. A cylindrical sleeve 31 extends through opening 30 andis welded to that wall of pipe 27. The longitudinal axis of sleeve 31 isin alignment with the longitudinal axis of the straight forward portionof tube 27. The sleeve 31 has a flange 32 at its external end. The toppart of an outside-screw and yoke type gate valve, generally indicatedat 33, is mounted on this external end of sleeve 31 with that top partof gate valve 33 having its bottom flange 34 connected conventionally bynuts and bolts to flange 32 of sleeve 31. The sleeve 31 and flange 34are separated by two annular packing rings 35.

The top part of gate valve 33 has a hand wheel 36 that operativelyengages the threaded end of a stem 37 that extends through sleeve 31into tube 27 where the I other end of stem 37 is connected to a tubularshaft 38. Mounted on the other end of tubular shaft 38 is a coupling 39that has at its other end a threaded hole in which is mounted a threadedrearward cylindrical extension 40 of a diverter generally indicated at41 made entirely of a suitable refractory material that is resistant tothe high temperature it will reach due to combustion in chamber 12 andthat is resistant to corrosion by the acid gas. Such material is asilicon nitride-bonded silicon carbide refractory, such as Refrax.

As seen in FIG. 1, the forward face of diverter 41 is dished but it maybe flat. The rearward portion of diverter 41 has a shape such that itssurface is frustoconical. The extension 40 of diverter 41 extendsrearwardly from the smaller dimension of this frustoconical surface. Theforward portion of the frustoconical surface faces the inner surface offlared end 29 of tube 27. This forward portion of the frustoconicalsurface of diverter 41 has a number of bosses 42, such as three of themequally spaced about the periphery of this surface, to abut the innersurface of flared end 29 if diverter 40 is moved to the left (as viewedin FIG. 1) a sufficient distance. This construction by preventing afurther movement of diverter 41 to the left by wheel 36 prevents closingof the annular passage between diverter 41 and flanged end 29 of pipe27.

Adjacent the forward end of tubular shaft 38, i.e., adjacent diverter41, tubular shaft 38 is provided with an intermediate support by aspider support generally indicated at 43. The support 43 comprises asleeve 44 with an inwardly turned flange at one end and that is internally threaded at the other end to serve as a gland housing. The support43 has radial plates 45 welded to sleeve 44 and to the inside surface oftube 27. Between sleeve 47 and tubular shaft 38 there is packed agaskettype, heat-resistant material enclosed in Monel mesh. A gland ring46 is forced against the gasket and kept in position by a gland nut 47that has its external threads engaging the internal threads of sleeve44. This construction provides support of tubular shaft 38 so as toprevent vibration at its forward end and thus prevent vibration ofdiverter 41. The latter vibration would be undesirable because it wouldchange the nature of the annulus between diverter 41 and flared end 29of tube 27. At the same time this construction permits axial movement ofshaft 38 and thus axial movement of diverter 41 while maintaining thisconcentric disposition of diverter 41 with respect to the forwardportion of tube 27.

In view of the foregoing description it is seen that coupling 39, shaft38 and stem 37 provide the shaft for the support of diverter 41 and thatthis shaft is supported at its rear end portion by support meansconstituting a top part of gate valve 33 that, at the same time, issupported by sleeve 31 mounted on and supported by tube 27 at its curvedexternal portion. It is also seen that the shaft that provides thissupport of diverter 41 has intermediate support means adjacent todiverter 41 by virtue of presence of spider support 43 that is fixedlymounted within the forward portion of tube 27, while permitting axialmovement of the shaft that supports diverter 41 for its axial movementwith respect to tube 27.

It is seen further that the top part of gate valve 33 in 5 combinationwith its support sleeve 31, fixedly 6 mounted on tube 27, constitutesmeans to move the shaft longitudinally and thus to move diverter 41mounted on its other end in either direction along the longitudinal axisof the forward portion of tube 27.

Referring to FIG. 3, there are several differences of construction ofburner 28. These differences are present because tube 27 external ofpipe 18 and plate 19 is straight rather than curved. As a result, tube27 has an opening 50 through which it receives acid gas from a pipe 51connected to pipe 27 at that point. The pipe 25, as in the constructionshown in FIG. 1, is connected to the air blower. The rearward end ofpipe 27 is closed by a plate 52 having a central opening 53 throughwhich extends sleeve 31 that is secured to plate 52.

Referring to FIG. 4, the diverter 41 has a different construction thanthat shown in FIG. 1 in that diverter 41 of FIG. 4 is not made of onematerial but has a composite construction. The unitary diverter 41 ofFIG. 4 includes a conical metal sheet 54 on the outside surface of whichare mounted metal bosses 42 for the purpose indicated above with respectto refractory bosses 42 of diverter 41 shown in FIG. 1. Of course, theconical sheet 54 has an outer frustoconical surface facing the flaredend of tube 27. The sheet 54 is welded to gussets 55 that are welded tothe forward end of tubular shaft 38. A number of bent wires 56 areattached to the front face of sheet 54 and have embedded in a castheatresistant, heat-insulating refractory 57 that is on the forward faceof plate 54. The refractory 57 has a sufficient thickness at the marginof conical plate 54 to avoid excessive heating of plate 54. The frontface of refractory 57 is dished to minimize the greater thick-.

ness of refractory 57 forward of the central portion of plate 54.

The frustoconical surface portion of diverter 41 of the burner of theinvention preferably has an included angle that is larger than that ofthe inner surface of the flared end of tube 27. This provides theadvantage of a smaller longitudinal movement of the diverter to providea given change in the area of the annular space between the diverter andthe tube.

The foregoing has presented preferred embodiments of the burner of thepresent invention. Many variations will be obvious to one skilled in theart in view of the foregoing description and the drawings. Theembodiments have been presented solely for the purpose of illustrationand not for the purpose "of limitation of the invention that is limitedonly by the claims that follow.

I claim:

1. An acid gas burner for feeding H S-containing gas to a combustionchamber of a thermal reactor of a sulfur plant, said burner including:

a gas-feeding tube having a forward cylindrical portion, that in useextends horizontally within, coaxial with and spaced from the forwardcylindrical portion of an air-supply tube and through a wall of thereactor into the chamber and that has a flared open end;

a gas diverter concentrically disposed in that open end to provide anannular space between said diverter and said open end of saidgas-feeding tube, said diverter having a rearward portion with afrustoconical surface having its outer margin facing the inner surfaceof that flared end of said gas-feeding tube at the annular space fordiverging forward outflow of acid gas from the gas-feeding tube;

a shaft connected to the rear end of said diverter and extendingrearwardly through the gas-feeding tube to an external location for theother end of said shaft, said shaft being concentrically disposed withrespect to the forward portion of said gas-feeding tube;

means adjacent said other end of said shaft to support said shaft;

means within the forward portion of said gas-feeding tube and adjacentsaid diverter to provide an intermediate support for said shaft, saidintermediate support means being supported by said forward portion ofsaid gas-feeding tube and being constructed to permit relative movementof said shaft with respect to said support means;

means mounted on said gas-feeding tube and operatively associated withsaid shaft adjacent said other end of said shaft to move and positionsaid shaft along its longitudinal axis for adjustment of the width ofthe annular space between said diverter and said flared open end of saidgas-feeding tube; and

means mounted on the burner to limit rearward axial movement of saiddiverter by said shaft to prevent closing of said annular space.

2. The burner of claim 1 wherein said diverter has bosses on saidouter'margin of said frustoconical surface facing said open end of saidgas-feeding tube to constitute said means to limit the rearward axialmovement of said diverter.

3. The burner of claim 2 wherein said diverter is a one-piece refractorymember that is resistant to corrosion by the acid gas and isheat-resistant.

4. The burner of claim 3 wherein said diverter is a siliconnitride-bonded silicon carbide refractory and wherein said diverter hasa rearward threaded cylindrical extension from said portion having saidfrustoconical surface, said burner further including means to couplesaid extension to the forward end of said shaft.

5. The burner of claim 2 wherein said diverter comprises:

a conical metal sheet;

gussets connected to said shaft and to said conical sheet to connectsaid sheet to said shaft; and

a cast refractory secured to the entire forward face of said conicalmetal sheet, said refractory having a dished front face, and

wherein said bosses are metal and are connected to the rearfrustoconical surface of said sheet at its margin.

6. An acid gas burner for feeding H S-containing gas to a combustionchamber of a thermal reactor, said burner including:

a gas-feeding tube having a forward cylindrical portion, that in useextends horizontally through a wall of the reactor into the chamber andhas a flared open end;

a gas diverter concentrically disposed in that open end to provide anannular space between said diverter and said flared open end of saidtube, said diverter having a rearward portion with a frustoconicalsurface having its outer margin facing the inner surface of that flaredopen end of said tube at the annular space for diverging forward outflowof acid gas from the tube;

a shaft connected to the rear end of said diverter and extendingrearwardly through the tube to an external location for the other end ofsaid shaft, said shaft being concentrically disposed with respect to theforward portion of said tube;

means adjacent said other end of said shaft to support said shaft;

means within the forward portion of said tube and adjacent said diverterto provide an intermediate support for said shaft, said intermediatesupport means being supported by said forward portion of said tube andbeing constructed to permit relative axial movement of said shaft withrespect to that support means;

means adjacent said other end of said shaft to move said shaftlongitudinally for axial movement of said diverter relative to saidflared open end of said tube; and

bosses on said outer margin of said frustoconical surface facing saidflared open end of said tube to limit the rearward axial movement ofsaid diverter by said shaft-moving means to prevent closing said annularspace,

said diverter being a one-piece member of silicon nitride-bonded siliconcarbide refractory and having a rearward threaded cylindrical extensionfrom said portion having said frustoconical surface, and said burnerfurther including means to couple said extension to the forward end ofsaid shaft.

7. An acid gas burner for feeding H s-containing gas to a combustionchamber of a thermal reactor, said burner including:

a gas-feeding tube having a forward cylindrical portion, that in useextends horizontally through a wall of the reactor into the chamber andhas a flared open end;

a gas diverter concentrically disposed in that open end to provide anannular space between said diverter and said flared open end of saidtube, said diverter having a rearward portion with a frustoconicalsurface having its outer margin facing the inner surface of that flaredopen end of said tube at the annular space for diverging forward outflowof acid gas from the tube;

a shaft connected to the rear end of said diverter and extendingrearwardly through the tube to an external location for the other end ofsaid shaft, said shaft being concentrically disposed with respect to theforward portion of said tube;

means adjacent said other end of said shaft to support said shaft;

means within the forward portion of said tube and adjacent said diverterto provide an intermediate support for said shaft, said intermediatesupport means being supported by said forward portion of said tube andbeing constructed to permit relative axial movement of said shaft withrespect to that support means;

means adjacent said other end of said shaft to move said shaftlongitudinally for axial movement of said diverter relative to saidflared open end of said tube; and

metal bosses mounted on said outer margin of said frustoconical surfacefacing said flared open end of said tube to limit the rearward axialmovement of said diverter by said shaft-moving means to prevent closingof said annular space,

said diverter comprising:

a conical metal sheet on the rear surface of which v said bosses aremounted;

gussets connected to said shaft and to said conical sheet to connectsaid sheet to said shaft; and

9 10 a cast refractory secured to the entire forward face feeding tubeto an external location for the other of said conical metal sheet, saidrefractory having end of said shaft, said shaft being concentrically adished front face. disposed with respect to the forward portion of 8. Athermal reactor for the oxidation by air of a part aid ga -feeding tube;of the 2 Content of the acid g t 2 which 5 means adjacent said other endof said shaft to supprises: port said shaft;

a housing providing a combustion chamber and havmeans within the f dPortion of id ing an opening in a wall;

means to supply air through the opening to the chamber, said meansincluding an air-supply tube having a forward cylindrical portionextending horizontally to said opening and said means being constructedso that air moving through the forward portion of said air-supply tubewill flow in a generally linear manner parallel to the longitudinal axisof the forward portion of that tube; and

a burner for feeding said acid gas through said opening in said housingto said combustion chamber, said burner including: a gas-feeding tubehaving a forward cylindrical portion within, coaxial with and spacedfrom said feeding tube and adjacent said diverter to provide anintermediate support for said shaft, said intermediate support meansbeing supported by said forward portion of said gas-feeding tube andbeing constructed to permit relative movement of said shaft with respectto said support means;

means mounted on said gas-feeding tube and operatively associated withsaid shaft adjacent said other end of said shaft to move and positionsaid shaft along its longitudinal axis for adjustment of the width ofthe annular space between said diverter and said flared open end of saidgasfeeding tube; and

forward portion of said aipsupply tube and means mounted on said burnerto limit rearward tending forwardly of said air supply tube into axialmovement of said diverter by said shaft to said housing, said forwardportion of said gasprevent closmg of Sam f feedingimbe at its open endbeing flared; 9. The thermal reactor of cla m 8 wherein. a gas diverterconcentrically disposed in that Open said diverter has bosses on saidouter margin of sa d end to provide an annular space between saiddifrustocolucal surface faclllg 531d PP and of l verter and said openend of said gas-feeding tube, gas'feedmg conslltute saldfnefms to id divh i a rearward i i h a the rearward axial movement of said diverter; andfr s i l Surface h i i outer margin f said diverter is a one-piecemember of silicon nitridein the i e s rfa of th fl d d f id bondedsilicon carbide refractory and has a reargas-feeding tube at the annularspace for divergward threaded cylindrical extension from said poringforward outflow of acid gas from the gastion having said frustoconicalsurface, feeding tube; said burner further including means to couplesaid exa shaft connected to the rear end of said diverter tension ofsaid diverter to the forward end of said shaft.

and extending rearwardly through the gas- UNITED STATES PATENT OFFICECERTIFICATE OF CORECTION Dated January 1, 1974 n Patent N 3.782.884

Inventofls) Willis L. Shumaker ,It is certified that error appears inthe above-identified patent and that said Letters Patent. are herebycorrected as shown below:

Column 1, line 57 "the end should read --that end--. Column 2, line 8,"throughout" should readthroughput. Column 3, line 55, "and" should readend--.-

Signed and sealed this 16th day of April 19714..

(SEAL) Attest:

EDWARD MQFLBTGHERJBQ 3. MARSHALL DANN Attesting Officer 5 Commissioneroi Patents USCOMM-DC come-Pea U.5. GOVERNMEN! FRINTTNG OFFICE: I909O-Jil334 FORM 1 0-1050 (10-69)

1. An acid gas burner for feeding H2S-containing gas to a combustionchamber of a thermal reactor of a sulfur plant, said burner including: agas-feeding tube having a forward cylindrical portion, that in useextends horizontally within, coaxial with and spaced from the forwardcylindrical portion of an air-supply tube and through a wall of thereactor into the chamber and that has a flared open end; a gas diverterconcentrically disposed in that open end to provide an annular spacebetween said diverter and said open end of said gas-feeding tube, saiddiverter having a rearward portion with a frustoconical surface havingits outer margin facing the inner surface of that flared end of saidgas-feeding tube at the annular space for diverging forward outflow ofacid gas from the gas-feeding tube; a shaft connected to the rear end ofsaid diverter and extending rearwardly through the gas-feeding tube toan external location for the other end of said shaft, said shaft beingconcentrically disposed with respect to the forward portion of saidgas-feeding tube; means adjacent said other end of said shaft to supportsaid shaft; means within the forward portion of said gas-feeding tubeand adjacent said diverter to provide an intermediate support for saidshaft, said intermediate support means being supported by said forwardportion of said gas-feeding tube and being constructed to permitrelative movement of said shaft with respect to said support means;means mounted on said gas-feeding tube and operatively associated withsaid shaft adjacent said other end of said shaft to move and positionsaid shaft along its longitudinal axis for adjustment of the width ofthe annular space between said diverter and said flared open end of saidgas-feeding tube; and means mounted on the burner to limit rearwardaxial movement of said diverter by said shaft to prevent closing of saidannular space.
 2. The burner of claim 1 wherein said diverter has bosseson said outer margin of said frustoconical surface facing said open endof said gas-feeding tube to constitute said means to limit the rearwardaxial movement of said diverter.
 3. The burner of claim 2 wherein saiddiverter is a one-piece rEfractory member that is resistant to corrosionby the acid gas and is heat-resistant.
 4. The burner of claim 3 whereinsaid diverter is a silicon nitride-bonded silicon carbide refractory andwherein said diverter has a rearward threaded cylindrical extension fromsaid portion having said frustoconical surface, said burner furtherincluding means to couple said extension to the forward end of saidshaft.
 5. The burner of claim 2 wherein said diverter comprises: aconical metal sheet; gussets connected to said shaft and to said conicalsheet to connect said sheet to said shaft; and a cast refractory securedto the entire forward face of said conical metal sheet, said refractoryhaving a dished front face, and wherein said bosses are metal and areconnected to the rear frustoconical surface of said sheet at its margin.6. An acid gas burner for feeding H2S-containing gas to a combustionchamber of a thermal reactor, said burner including: a gas-feeding tubehaving a forward cylindrical portion, that in use extends horizontallythrough a wall of the reactor into the chamber and has a flared openend; a gas diverter concentrically disposed in that open end to providean annular space between said diverter and said flared open end of saidtube, said diverter having a rearward portion with a frustoconicalsurface having its outer margin facing the inner surface of that flaredopen end of said tube at the annular space for diverging forward outflowof acid gas from the tube; a shaft connected to the rear end of saiddiverter and extending rearwardly through the tube to an externallocation for the other end of said shaft, said shaft beingconcentrically disposed with respect to the forward portion of saidtube; means adjacent said other end of said shaft to support said shaft;means within the forward portion of said tube and adjacent said diverterto provide an intermediate support for said shaft, said intermediatesupport means being supported by said forward portion of said tube andbeing constructed to permit relative axial movement of said shaft withrespect to that support means; means adjacent said other end of saidshaft to move said shaft longitudinally for axial movement of saiddiverter relative to said flared open end of said tube; and bosses onsaid outer margin of said frustoconical surface facing said flared openend of said tube to limit the rearward axial movement of said diverterby said shaft-moving means to prevent closing said annular space, saiddiverter being a one-piece member of silicon nitride-bonded siliconcarbide refractory and having a rearward threaded cylindrical extensionfrom said portion having said frustoconical surface, and said burnerfurther including means to couple said extension to the forward end ofsaid shaft.
 7. An acid gas burner for feeding H2S-containing gas to acombustion chamber of a thermal reactor, said burner including: agas-feeding tube having a forward cylindrical portion, that in useextends horizontally through a wall of the reactor into the chamber andhas a flared open end; a gas diverter concentrically disposed in thatopen end to provide an annular space between said diverter and saidflared open end of said tube, said diverter having a rearward portionwith a frustoconical surface having its outer margin facing the innersurface of that flared open end of said tube at the annular space fordiverging forward outflow of acid gas from the tube; a shaft connectedto the rear end of said diverter and extending rearwardly through thetube to an external location for the other end of said shaft, said shaftbeing concentrically disposed with respect to the forward portion ofsaid tube; means adjacent said other end of said shaft to support saidshaft; means within the forward portion of said tube and adjacent saiddiverter to provide an intermediate support for said shaft, saidintermediate support means being supported by said forward portion ofsaid tube and being constructed to permit relative axial movement ofsaid shaft with respect to that support means; means adjacent said otherend of said shaft to move said shaft longitudinally for axial movementof said diverter relative to said flared open end of said tube; andmetal bosses mounted on said outer margin of said frustoconical surfacefacing said flared open end of said tube to limit the rearward axialmovement of said diverter by said shaft-moving means to prevent closingof said annular space, said diverter comprising: a conical metal sheeton the rear surface of which said bosses are mounted; gussets connectedto said shaft and to said conical sheet to connect said sheet to saidshaft; and a cast refractory secured to the entire forward face of saidconical metal sheet, said refractory having a dished front face.
 8. Athermal reactor for the oxidation by air of a part of the H2S content ofthe acid gas to SO2 which comprises: a housing providing a combustionchamber and having an opening in a wall; means to supply air through theopening to the chamber, said means including an air-supply tube having aforward cylindrical portion extending horizontally to said opening andsaid means being constructed so that air moving through the forwardportion of said air-supply tube will flow in a generally linear mannerparallel to the longitudinal axis of the forward portion of that tube;and a burner for feeding said acid gas through said opening in saidhousing to said combustion chamber, said burner including: a gas-feedingtube having a forward cylindrical portion within, coaxial with andspaced from said forward portion of said air-supply tube and extendingforwardly of said air-supply tube into said housing, said forwardportion of said gas-feeding tube at its open end being flared; a gasdiverter concentrically disposed in that open end to provide an annularspace between said diverter and said open end of said gas-feeding tube,said diverter having a rearward portion with a frustoconical surfacehaving its outer margin facing the inner surface of that flared end ofsaid gas-feeding tube at the annular space for diverging forward outflowof acid gas from the gas-feeding tube; a shaft connected to the rear endof said diverter and extending rearwardly through the gas-feeding tubeto an external location for the other end of said shaft, said shaftbeing concentrically disposed with respect to the forward portion ofsaid gas-feeding tube; means adjacent said other end of said shaft tosupport said shaft; means within the forward portion of said gas-feedingtube and adjacent said diverter to provide an intermediate support forsaid shaft, said intermediate support means being supported by saidforward portion of said gas-feeding tube and being constructed to permitrelative movement of said shaft with respect to said support means;means mounted on said gas-feeding tube and operatively associated withsaid shaft adjacent said other end of said shaft to move and positionsaid shaft along its longitudinal axis for adjustment of the width ofthe annular space between said diverter and said flared open end of saidgas-feeding tube; and means mounted on said burner to limit rearwardaxial movement of said diverter by said shaft to prevent closing of saidannular space.
 9. The thermal reactor of claim 8 wherein: said diverterhas bosses on said outer margin of said frustoconical surface facingsaid open end of said gas-feeding tube to constitute said means to limitthe rearward axial movement of said diverter; and said diverter is aone-piece member of silicon nitride-bonded silicon carbide refractoryand has a rearward threaded cylindrical extension from said portionhaving said frustoconical surface, said burner further including meansto couple said extension of said diverter to the forward end of saidshaft.